Thanks for the props on the gear detail guys.

Abu,
It's a combination of building up a stock set of gear using styrene, PVC, epoxy, etc., to build up the strut and create all the bosses and standoffs, etc., then creating masters for all the other parts and pieces, then making individual molds and resincasting parts from them.
If you followed Tom Pierce's Dauntless thread, then you'll have an idea of the similar techniques I use make the master parts.

Then, once you have all your parts mastered, use molding rubber to make 1, 2 and even 3-part molds, then create castings from them. I use Alumilite products...although there are others.
Molds cure in 12-24 hrs., and the Resin cures in minutes.

The tricky part is knowing how to create the molds properly so that they don't trap air, etc., and don't contain undercuts that trap the part. On parts that have bolt holes, cast them with various wire and brass rods inserted into the cavity so that when removed from the mold, it leaves holes in the finished part that simply need to be tapped, for attaching with bolts and screws.
This allows for the consistent fit of parts from set to set. It also allows replacement parts to be interchanged. and it keeps from having to figure out where to drill holes, every time you fabricate a new set.
After all the parts have been cast, it's like American Chopper. Fabricate the entire build, disassemble, paint and detail, then final assembly.

It's all definitely a learning process, like everything else. But, as with anything, it's the initial effort that sets the tone for the final work.
The molds pick up very fine detail, so the quality of the parts is only as good as the masters they're replicated from.

Getting the first set completed requires a three step process of Fabricating Masters, Molding/Casting and Assembly Paint Detail. They each take about the same amount of time, which on a project as intense a the F/A-18 landing gear (lots of parts and detail) required upwards of 350 hours of work. It takes me about 150 hrs. to do a set from the molds.

It is a fun process, and the possibilities really open up once you get the hang of it. It becomes tedious after the first few sets because of the exhorbitant amount of work invlvolved in the hand-fabricating environment.

All this means that these suckers aren't cheap, and are not for the faint of heart.

I would suggest everyone give resin-casting a try on any project that requires two or more of something. Think of how many times you need to create sevral of the same thing and kinda made them all just "OK" to get through 'em. (Wheels, Exhaust Stacks, GPS Antennae, Fuel Caps, Control Yokes, etc.)
Well I suggest spending twice the time making one just perfect, with the finest detail, them make as many copies as you wish.

It's fun...try it.

Sorry for the lengthy rambling post.

Paul